Organotin process

ABSTRACT

This invention is a method for preparing compounds of the formula R3SnSnR3 comprising pyrolyzing a triorganotin formate of the formula   WHEREIN R is a hydrocarbon selected from the group consisting of alkyl, alkenyl, aralkyl, and cycloalkyl radicals, and separating R3SnSnR3.

United States Patent 11;;

Reifenberg et al.

[ ORGANOTIN PROCESS [75] Inventors: Gerald B. Reifenberg, l-lightstown', William J. Considine, Somerset both [21] App]. No. 88,238

Related US. Application Data [62] Division of Ser. No. 773,329, Nov. 4, 1968, Pat. No.

[52] US. Cl ..260/429.7 [51] Int. Cl. ..C07i 7/22 [58] Field of Search ..260/42 9.7

[ 51 Apr. 10, 1973 [5 6] References Cited I UNITED STATES PATENTS 3,439,010 4/1969 ltami et al. ..260/429.7

Primary Examiner-Werten F. W. Bellamy Attorney--Lewis C. Brown et al.

[57] ABSTRACT This invention is a method for preparing compounds of the formula lQSnSnR comprising pyrolyzing a triorganotin formate of the formula 0 RiSnO 91H wherein R is a hydrocarbon selected from the group consisting of alkyl, alkenyl, aralkyl, and cycloalk radicals, and separating R SnSnR 4 Claims, No Drawings ORGANOTIN PROCESS This application is a divisional application of Ser. No. 773,329, filed on Nov. 4, 1968, now U.S. Pat. No. 3,652,618.

This invention relates to a novel process for producing organotin compounds.

This invention is a method for preparing compounds of the formula R SnSnR comprising pyrolyz'ing a triorganotin formate of the formula RzSnO i111 wherein R is a hydrocarbon selected from the group consisting of alkyl, alkenyl, aralkyl, and cycloalkyl radicals, and separating R SnSnR According to another of its aspects, the method of this invention for preparing compounds R SnSnR comprises heating a first moiety of triorganotin formate of the formula 0 RzSnO H to form triorganotin hydride of the formula R SnH wherein R is a hydrocarbon radical selected from the group consisting of alkyl, alkenyl, aralkyl, and cycloalkyl, reacting as reactants said triorganotin hydride and a second moiety of triorganotin formate at a temperature of at least about 100 C., and recovering R SnSnR Typical triorganotin formate starting materials operable in the practice of this invention include: triethyltin formate, tri-n-propyltin formate, tri-n-butyltin formate, tri-n-amyltin formate, tri-n-octyltin formate, and tricyclohexyltin formate.

1n the reactant R is a hydrocarbon radical preferably selected from the group consisting of alkyl, alkenyl, cycloalkyl, and aralkyl including such radicals when inertly substituted. When R is alkyl, it may typically be straight chain alkyl or branched alkyl, including ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-amyl, neopentyl, isoamyl, n-hexyl, isohexyl, heptyls, octyls, decyls, dodecyls, tetradecyl, octadecyl, etc. Preferred alkyl includes lower alkyl, i.e. having less than about nine carbon atoms, i.e. octyls and lower. When R is alkenyl, it may typically be vinyl, allyl, l-propenyl, methallyl, buten-lyl, buten-2-yl, penten-l-yl, hexenyl, heptenyl, octenyl, decenyl, dodecenyl, tetradecenyl, octadecenyl, etc. When R is cycloalkyl, it may typically be cyclopentyl, 'cyclohexyl, cycloheptyl, cyclooctyl, etc. When R is aralkyl, it may typically be benzyl, B-phenylethyl, vphenylpropyl, B-phenylpropyl, etc. R may be inertly substituted, e.g., may bear a non-reactive substituent such as alkyl, cycloalkyl, aralkyl, alkenyl, ether, ester, etc. Typical substituted alkyls include 2-etho' xyethyl, carboethoxymethyl, etc. Substituted alkenyls include 11- phenylpropenyl, etc. Substituted cycloalkyls include 4- methylcyclohexyl, etc. lnertly substituted aralkyl includes p-phenylbenzyl, p-methylbenzyl, etc.

In the practice of this invention it is desirable to use an inert diluent. Typical inert diluents include inert hydrocarbons such as benzene, toluene, etc., and aliphatic hydrocarbons including hexane, heptane, oc-

tane, etc. Preferably the solvent is one which has a boiling point at atmospheric pressure of at least about 100C, and typically 100C to 200C.

The reaction of this invention is preferably carried out under inert atmosphere, e.g. nitrogen, since the products, e.g. hydrides and ditins may be oxidized by oxygen.

In carrying out the novel reaction of this invention, the raw material is maintained at 150C to 200C for 2 hours to 12 hours.

In the practice of this invention the following reactions may occur .0 ll R SnOCH RaSnH C02 0 R Snl-I R SnOH RaSnSnR: HiiOH Trialkyltin hydrides formed as intermediates in the practice of this invention include triethyltin hydride, tri-n-propyltin hydride, tri-isopropyltin hydride, tri-noctyltin hydride, and tricyclohexyltin hydride.

At the completion of the reaction, after the byproducts have been removed, the product may be separated and recovered by conventional means. When the product is present together with the diluent, the product, if insoluble in the diluent, may be filtered, washed, and further purified if desired. If the pure product is soluble in the diluent it may be separated by distillation under reduced pressure.

For the purpose of giving those skilled in the art a better understanding of the invention, reference is made to the following examples.

EXAMPLE 1 Preparation of hexabutylditin.

Into a reaction vessel maintained under an atmosphere of nitrogen, 50.0 grams (0.15 mole) of tributyltin formate was introduced. The two-necked, 100 milliliter reaction vessel was fitted with a magnetic stirring bar, a water condenser, and a thermometer. The tributyltin formate was heated at temperatures ranging from 150C to 185C for 1 1.5 hours during which time a flow of nitrogen gas was maintained by the reaction vessel. At the end of 11.5 hours, the reaction mass exhibited a weight of 38.3 grams. Vapor phase chromatographic analysis of the product showed that the yield of hexabutylditin was 77.5 percent of the reaction mass, tributyltin formate was 10.4 percent of the reaction mass, tetrabutyltin was 5.2 percent and tributyltin hydride was 6.9 percent.

EXAMPLE 2 was distilled under vacuum using a fractionating head.

The distillate exhibited a weight of 48.3 grams. Vapor phase chromatographic analysis of the product showed percent of the reaction mass and propyltin that the yield of hexapropylditin was 42.0 percent of the distillate.

EXAMPLE 3 Preparation of hexabutylditin.

Into a reaction vessel maintained under an atmosphere of nitrogen was introduced 1 1.6 grams (0.04 mole) of tributyltin hydride and 13.4 grams (0.04 mole) of tributyltin formate. The reaction mixture was heated at a temperature of 145C to 165C for 5.5 hours. Vapor phase chromatographic analysis of the product showed that the yield of hexabutylditin was 54.5 percent of the reaction mass. Tributyltin formate was 33.8 percent of the reaction mass and tributyltin hydride was 5.3 percent.

EXAMPLE 4 second moiety of triorganotin formate at a temperature pounds of this inventionare useful as catalysts for a polymerization of ethylene and propylene. For example, they are also used in the polymerization of diene hydrocarbons having conjugated double bonds in the presence of cobalt or nickel compounds and aliminumhalides, e.g. cobalt naphthenate and aluminum.

Although this invention has been illustrated by reference to specific examples, numerous changes and modifications thereof which clearly fall within the scope of the invention will be apparent to thoseskilled in the art.

We claim:

1. A method for preparing compounds RgSnSnR comprising heating a first moiety of triorganotin formate of the formula 9 msno to form triorganotin hydride of the formula R SnH wherein R is a hydrocarbon radical selected from the group consisting of alkyl, alkenyl, aralkyl, and cycloalkyl reacting as reactants said triorganotin hydride and a of at least about 100C, and recovering R SnSnR 2. The process of claim 1 wherein R exhibits less than 9 carbon atoms.

3. The process of claim 1 wherein R is propyl. 4. The process of claim 1 wherein R is butyl. 

2. The process of claim 1 wherein R exhibits less than 9 carbon atoms.
 3. The process of claim 1 wherein R is propyl.
 4. The process of claim 1 wherein R is butyl. 